It's apparently browser engine day today. After Mozilla and Samsung announcing Servo, Google has just announced it's forking WebKit into Blink. Like WebKit, Blink will be open source, and it will also be used by other browser makers - most prominently, Opera has already announced it's not using WebKit, but Blink. Update:Courtesy of MacRumors, this graph illustrates how just how much Google contributed to WebKit. Much more than I thought. Also, Chrome developer Alex Russell: "To make a better platform faster, you must be able to iterate faster. Steps away from that are steps away from a better platform. Today's WebKit defeats that imperative in ways large and small. It's not anybody's fault, but it does need to change. And changing it will allow us to iterate faster, working through the annealing process that takes a good idea from drawing board to API to refined feature."

The reasons for forking WebKit, according to Google, are architectural. For instance, Chromium uses a different multi-process architecture than WebKit itself, which leads to a lot of additional code complexity for both Chromium and WebKit.

WebKit vs Chromium is old story: Since inception of Google Chrome.

This is 21 month old document:

"Chromium WebKit does not directly provide a multiprocess framework, rather, it is optimized for use as a component of a multiprocess application, which does all the proxying and process management itself. The Chrome team at Google did a great job at trailblazing multiprocess browsing with Chrome. But it's difficult to reuse their work, because the critical logic for process management, proxying between processes and sandboxing is all part of the Chrome application, rather than part of the API layer."